Self-balancing aeroplane.



C. T. LITCHPIELD & R. D. McKAY.

SELF BALANCING ABROPLANE. APPLIGATION FILED MAY 15, 1911.

Patented Dec. 12, 1911.

3 SHEETSSHEET 1.

SELF BALANCING AEBOPLANE.

APPLIUATION FILED MA-Y15, 1911. I 1,01 1,354, I Patented Dec.12,1911.

3 SHEETS-SHEET 3.

7 To all whom it may concern:

cnmns '1. LIToHFIELD, or

SELF-BALANCING. AERQPLANE.

Be it known that we, CHARLES T. Lrrcrr- FIELD, of Rosalia, in the countyof VVhitman and State of Washington, and.RALPH D. MCKAY, of Tacoma, inthe county of Pierce and State -of Washington, citizens of the UnitedStates, have invented a certain new and useful Improvement inSelf-Balane' 1ng Aeroplanes, of which the following is a full, clear,and exact description.

- The object of this invention is to provide anla rship of theaeroplane, biplane type, whichwill for all 7 practical purposes beself-balancing.

The main body of the apparatus comprises a'biplane with a-substantiallycentral backbone, in which the propeller is mounted in an adjustablemanner at the front of the body," and vertical'and horizontal ruddersarearranged at'the end of the backbone, and horizontal balancing planesarranged at 0p positeen ds' of the body and connected with anautomatically operating adjusting mechanism connected with the main bodyor backbone in'such way that there may be a rela tive movement of theadjusting mechanism.

as the body tilts sidewise in order to adjust the balancing planescorrespondingly. V

The invention consists of these'featu'res and others collateral theretoin the control of the movements or flight of the machine.

I In the accompanyingdrawings, illustrating the invention, in theseveral figures of which a like parts are similarly designated, Figure 1is 'a top plan View. Fig. 2 is an elevation of the adjusting mechanismdetached and with the body level, and Fig. 3 is f a'similar view of saidmechanism with the "body tilted. Fig. 4: is a front elevation.

Fig. 5 is a rear elevation. Fig. 6 is a side elevation. Fig. 7 is a planview on a larger scale, of one form of propeller adjusting mechanism,and Fig. 8 is a side elevation thereof. 3 a

tion, comprising posts 3 and stringers l, and suitablecovering, withsuitable stays 5 ;and

"the backb'oneor tail likewise may consist of i suitable posts 6,stringers 7, and stays 8. 'i The mainframe or body carries any su1t-"able motor 9, having a shaft 10 provided with a--,-,sprocket wheel 11,connected by a ftransmissiondevioe 12 with a sprocket wheel 13 o1i-'thepropeller shaft 14;, and said' 'pro- B L ANI) RALPH n. rrcmyjjASHINGTON, c

Specification of Letters Patent,

Application filed May 15, 1911. Ser l), 627,275; I

Patented e peller shaft has a i the.

in which is mounted the yoke. a

stub shaft 17 on whichthe propellep ls js directly mounted, and this stubyshaf nected by a universal joint tilted to any desired angle; ;'I hetilting mechanism may comprise .a toothedesegment 20 meshing with aworm--21. om the; shaft 22 reaching back through the mainframe, andprovided with a hand-wheel 2&1Within convenient reach of the. aatiatorflllhe invention, however, is not-limited.-,to. any'of these details,and they may; b.e.-;a,ltered at pleasure. g

At the ends of the main frame remounted the horizontal planes -24,hereinreferred to as the balancing planes, otherwise ailerons or warpingwings or. devices, and

these balancingplanes aret connecte'qlgaby; aa-zi cord or other suitablemediuingwith the,ends of the adjusting 11'18Cha11lSl11,:1S0;thatwthebalancing planes are tiltedin accordance; with the relativeinclination ofithe'. mainbodyand the adjusting mechanism. j

The mechanism forv adjusting the balancing planes in accordance with thetilt of the aeroplane, comprises a rigidgfra nefl, fixed to the bottomof the main body; and having 1 pivoted in it two pendulums 26 of likecon struction, and these pendulums:l1a;ve .-a;.loose connection with arod 27"WlllQlldSflQIkIlQClQEd at opposite ends to the endlesscord ,whichin turn is connectedto the balanciIig-PhtneS at opposite 'ends of thebody! .AspringQQS); is arranged upon the rOdQZ-Zbetiveen thependulums,'and the pendulumsgare heldsubstantially parallel.againstcthe, .th1ju ofthe spring by means of fixed-'ibuttons fi on therod. Each pendulum is-supplied j'with quadrant, sector orbellfcranklever 3.1 and these quadrant levers are connected by-linkswith a portionof the rigid?frart-re; Each quadrant lever has a latch-33jextending up- The planes 1 and 2" of the main body may be of any usualor approved construc-- wardly through a guide ::3 l-- 2 u1d supplied;with a contact face 35,1 01? cooperation. with the respective buttonswas i the -body-tilts sidewise. -As shown in Fig.";-2,--thezlatches areout of contact withthe buttonsewhen the machine is on a level,andwhenthe machinet is tilted, the pendulum on thedownwardly inclined sidewill swing out-and .its'i quadrant lever will beactuatedrsoasitothrowthe.

.li it. 1,. .1 s 14 in such way that tl1epropeller;, may be latch intocontact with theadjacentbutton and thereby draw uponthat'side.ofithegend less cord 28, so as to effect an adjustment of thebalancing planes. The companion pendulum is unaffected and remains inits original position. 1

The adjusting mechanism may be put any where under the body, inthe-center, or with one of the pendulums on each side of the .center,and each pendulum is limited in its action, swinging only through ashort are of a circle, or in'other words, through one half of the arc ofthe circle traversed by the two. This provision. is made in order toovercome'the oscillation of the pendulums when the machine comes to alevel.

It will be understood that the latches normally tend to engage thebuttons when the aeroplane tilts, the latch on the downwardly inclinedside receiving a vertical motion through the action of the link andquadrant and rising into position behind the button and therebyimparting motion to the balancing planes through the endless connectingcord 28, as already indicated. It will be observed that the endlessconnecting cord will receive motion from one pendulum only at a. time.

As clearly indicated in Figs. 2, 4 and 5, the adjusting mechanism isnormally inactive when the aeroplane is level. ,As the machine comes toa level after tilting, the

latch is thereby thrown out of contact with the button and the pendulumcomes to a rest at a definite point, and cannot swing about the center.A pair of pendulums is necessary in order to obtain a cessation. ofmovement of the balancing planeswhen none is required. A pair ofpendulums also avoids the constant oscillation that a single pendulumwould have, and, consequently, avoids the continual adjustment of thebalancing lanes that would be incident to the use of a single pendulum.

It will be observed that each pendulum operates in one direction y toeffect movement of thebalancing planes operating cord.

The operation has been described with respect to the right handpendulum, but what has been said of that applies equally to the lefthand pendulum when the machine is tilted downwardlyin that direction.

By the term rod as applied to the device 27 and the term cord as appliedto the device 28, we do not intend to limit our invention to anyparticular material for forming the endless or other connection betweenthe balancing planes 24 and the pendulums, and we use the term endlessmerely as a convenient designation to indicate that these parts are soconnected that both planes are operated simultaneously andcomplementally by the respective pendulums as they respectively swingunder the inclination of the machine.

36 is a vertical rudder placed at the end of the backbone or tail, andconnected by cords 37 with the foot-lever 38 within convenient reach ofthe aviator. The tail also has a pair of horizontal rudders 39 mountedto work together and connected by a cord or other medium 40 which ektends to a lever 41 mounted on the main frafme within reach of theaviator.

If desired, a fixed wheel 42 may be mounted beneath the backbone andfixed wlieels 43 may be mounted beneath the body for supportin themachine when it is upon the groum and for starting and landing purposes.

The propeller maybe tilted backward or forward relatively to the mainbody in order,

the curtains, the unrolling" being effected by cords connected therewitl:nd brought into convenient reach of the a. .ator;

In starting the machine firom the ground, the propeller may be tilte,point upward, and the horizontal rudders 39 may be given a similar tilt,and then the machine run a short distance on the ground.

It will be noted that in the operation, the

main frame, are simultaneously tilted in opposite directions and theeffect of this actio is to keep the machine balanced.

What we claim'is':

1. A self-balancing aeroplane, having a main body, horizontal balancingplanes arranged at the extremities of the main body, a pair ofpendulums, and means to connect the balancing planes and the pendulums,so that said balancing planes will be adjusted in accordance with themotions of the main body, and means to compel the pendulums to swingaway from the center of motion in one direction and restrain them frompassing such center in the opposite direction.

2. In an aeroplane, the combination ofa main body, balancing planes atits opposite ends, and an automatically operated adjusting mechanism forsaid balancing planes, conslstlng of an endless cord connectlng saidendless operating cord connecting them, in

nary spring curtain roller, acting to roll up balancing planes 24 atopposite ends of the aeroplane is tilted toward one or the other.'

4. In an aeroplane, the combination with a body having balancing planesat its ends, .an endless operating cord, a pair of pendulums connectedat one end with said operating cord loosely, and means carried by saidpendulums to independently connect said pendulums rigidly with theoperating cord as the aeroplane is tilted toward the said pendulum,

5. In-an aeroplane, the combination with a body having balancing planesat its ends, an endless operating cord, a pair of pendulums connected atone end with said operating cord loosely and yieldingly, and meanscarried by said pendulums to independently connect said pendulumsrigidly with the operating cord as the aeroplane is tilted toward thesaid pendulum.

6. In an aeroplane, the combination of a body having balancing planes atopposite ends, and an endless operating cord connecting said balancingplanes, of independently pivoted pendulums connected with the endlessoperating cord loosely, a carrier in which said pendulums are suspendedfrom the body of the aeroplane, a latch mounted upon each pendulum, asector lever pivoted in each pendulum and carrying the latch,

and a link for connecting the sector lever with the pendulum carrier,the construction and arrangement being such that only that pendulummoves which is next to the downwardly inclined side of theaeroplanerelative to its center of motion, while the other pendulumremains quiet and 'unafiected.

7. In an aeroplane, the combination of a body having balancing planes atopposite ends, and an endless operating cord connecting the saidbalancing planes, of independently pivoted pendulums connected with theendless operating cord loosely, a carrier in which said pendulums aresuspended from the body of the aeroplane, buttons on the endlessoperating cord outside of the pendulums, a latch mounted upon-eachpendulum, a sector lever pivoted in each pendulum and carrying thelatch, and a link for connecting the sector lever with the pendulumcarrier, the construction and arrangement being such that only thatpendulum moves which is next to the downwardly inclined side relativelyto the center of motion of the aeroplane, while the other pendulumremains quiet and unaffected, the latch of the swinging pendulumengaging the button on the endless operating cord and serving to shiftthe cord and both balancingplanes thereby to restore and maintain theproper level of the aeroplane.

8. In a self balancing aeroplane, means for propelling it, anautomatically operating duplex pendulum arranged beneath the aeroplane,and balancing planes arranged at opposite ends of the body and connectedwith the duplex pendulum so as to partake of the oscillations of theaeroplane, and means to compel the pendulum to swing away from itscenter of motion and restrain it from swinging beyond such center in theopposite direction.

In testimony whereof, we have hereunto set our hands.

,CHARLES T. LITCHFIELD.

RALPH D. MoKAY. Witnesses as to Charles T. Litchfield:

T. R. HAUBLER, A. S. KING.

Witnesses as to Ralph D. McKay:

E. F. MAREK, H. B. Rrrz.

